This invention relates to a test set useful in detecting hepatitis associated antigen in human body fluid.
Hepatitis B, formerly known as "serum hepatitis," is a disease which may be contracted by the parenteral or nonparenteral introduction of the hepatitis causative agent. Each year, in the United States alone, thousands of persons contract the disease after having received a transfusion of blood originating from a donor who has the causative agent in his blood. Since the disease has an incubation period lasting up to several months, a blood donor who as yet has not experienced any of the symptoms of hepatitis can unwittingly transmit the disease to an unsuspecting victim.
Those who contract hepatitis B invariably develop a hepatitis associated antigen in their blood streams. While, as yet, it is not known whether these antigens are themselves the causative agent of the disease, it is currently the best marker for the presence of that agent. Since the fairly recent discovery of a hepatitis associated antigen, a number of clinical detection procedures have been devised. These seek to provide a routine test, which can be performed on serum or plasma from blood samples and which is capable of screening blood containing the hepatitis associated antigen.
One such test is disclosed in U.S. copending application Ser. No. 617,743, entitled Method of Determining the Presence of an Antigen Associated with Hepatitis, by Seymour P. Halbert et al., filed on even date herewith, the disclosure of which is incorporated herein by reference. Briefly, the procedure involves incubating a small sample of fluid with an insoluble disc coated with purified antibodies reactive with antigens associated with hepatitis antigens. If hepatitis are present in the fluid, an immunochemical bond forms between the antigen and the immobilized hepatitis antibody. After washing away any soluble materials, the insoluble disc is subjected to a second incubation, this time with an enzyme tagged conjugate reagent. In the event antigen was present in the sample, a second immunochemical bond forms between the immobilized antigen on the disc and the enzyme tagged antibody. After another washing to remove any unbonded material, the disc is subjected to a third incubation with a substrate which, under the catalytic influence of the now immobilized enzyme, undergoes a chemical reaction to form a detectable end product. This end product can be present in the solution only if hepatitis antigens were present in the sample, since otherwise, no enzyme is immobilized, and the end product cannot be produced.
This procedure enables many samples, e.g., 100, to be tested simultaneously in about a 4 hour period. However, the success of the test, and particularly its sensitivity, is dependent, inter alia, on the concentrations and purity of the reagents used, the relative amounts of reagents used, and the degree of care employed by the technician during the procedure. Consequently, in order for the test to serve as a reliable and routine procedure for the detection of the hepatitis antigen, it is imperative that the reagents, reaction containers, etc., be supplied in a fashion designed to minimize human error, simplify the procedure, and standardize the steps involved so that accuracy and reproducibility may be easily maintained.
Accordingly, it is an object of the present invention to provide a unitized test set which is adapted for the performance of a sensitive, reproducible immunoassay of antigens associated with hepatitis on a routine basis by relatively unskilled persons.
Another object of the invention is to provide such a test set which is designed to minimize procedural errors in the performance of the immunoassay and which contains all the necessary reagents, reaction containers, etc. in a form designed to optimize the accuracy and sensitivity of the test.
Another object of the invention is to provide a test set containing laboratory equipment designed to standardize the various steps performed during the assay.
Still another object of the invention is to provide a test set containing standard control samples, negative, weakly positive, and strongly positive for hepatitis associated antigen, with which the test samples may be compared.